Ruby On Rails
Ruby is a pure OO based programming language (unlike Java which contains primitives), and is a cross between Smalltalk and Perl. Rails is a full-stack framework for developing modern web applications (connected to a relational database), in accordance, to the Model-View-Control design pattern. From the AJAX-enabled in the view, to the request and response in the controller, to the domain model wrapping the database, Rails provides the developers with a pure-Ruby development environment. To go live, all you need to add is a database and a web server.
One of the key features of Rails is that it has code generators that build the loosely coupled components for you. Therefore, this innovative framework, feels like its got XP-style programming, built-in.